1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright(c) 2017 Intel Corporation. All rights reserved. |
4 | */ |
5 | #include <linux/libnvdimm.h> |
6 | #include <linux/badblocks.h> |
7 | #include <linux/export.h> |
8 | #include <linux/module.h> |
9 | #include <linux/blkdev.h> |
10 | #include <linux/device.h> |
11 | #include <linux/ctype.h> |
12 | #include <linux/ndctl.h> |
13 | #include <linux/mutex.h> |
14 | #include <linux/slab.h> |
15 | #include <linux/io.h> |
16 | #include "nd-core.h" |
17 | #include "nd.h" |
18 | |
19 | void badrange_init(struct badrange *badrange) |
20 | { |
21 | INIT_LIST_HEAD(list: &badrange->list); |
22 | spin_lock_init(&badrange->lock); |
23 | } |
24 | EXPORT_SYMBOL_GPL(badrange_init); |
25 | |
26 | static void append_badrange_entry(struct badrange *badrange, |
27 | struct badrange_entry *bre, u64 addr, u64 length) |
28 | { |
29 | lockdep_assert_held(&badrange->lock); |
30 | bre->start = addr; |
31 | bre->length = length; |
32 | list_add_tail(new: &bre->list, head: &badrange->list); |
33 | } |
34 | |
35 | static int alloc_and_append_badrange_entry(struct badrange *badrange, |
36 | u64 addr, u64 length, gfp_t flags) |
37 | { |
38 | struct badrange_entry *bre; |
39 | |
40 | bre = kzalloc(size: sizeof(*bre), flags); |
41 | if (!bre) |
42 | return -ENOMEM; |
43 | |
44 | append_badrange_entry(badrange, bre, addr, length); |
45 | return 0; |
46 | } |
47 | |
48 | static int add_badrange(struct badrange *badrange, u64 addr, u64 length) |
49 | { |
50 | struct badrange_entry *bre, *bre_new; |
51 | |
52 | spin_unlock(lock: &badrange->lock); |
53 | bre_new = kzalloc(size: sizeof(*bre_new), GFP_KERNEL); |
54 | spin_lock(lock: &badrange->lock); |
55 | |
56 | if (list_empty(head: &badrange->list)) { |
57 | if (!bre_new) |
58 | return -ENOMEM; |
59 | append_badrange_entry(badrange, bre: bre_new, addr, length); |
60 | return 0; |
61 | } |
62 | |
63 | /* |
64 | * There is a chance this is a duplicate, check for those first. |
65 | * This will be the common case as ARS_STATUS returns all known |
66 | * errors in the SPA space, and we can't query it per region |
67 | */ |
68 | list_for_each_entry(bre, &badrange->list, list) |
69 | if (bre->start == addr) { |
70 | /* If length has changed, update this list entry */ |
71 | if (bre->length != length) |
72 | bre->length = length; |
73 | kfree(objp: bre_new); |
74 | return 0; |
75 | } |
76 | |
77 | /* |
78 | * If not a duplicate or a simple length update, add the entry as is, |
79 | * as any overlapping ranges will get resolved when the list is consumed |
80 | * and converted to badblocks |
81 | */ |
82 | if (!bre_new) |
83 | return -ENOMEM; |
84 | append_badrange_entry(badrange, bre: bre_new, addr, length); |
85 | |
86 | return 0; |
87 | } |
88 | |
89 | int badrange_add(struct badrange *badrange, u64 addr, u64 length) |
90 | { |
91 | int rc; |
92 | |
93 | spin_lock(lock: &badrange->lock); |
94 | rc = add_badrange(badrange, addr, length); |
95 | spin_unlock(lock: &badrange->lock); |
96 | |
97 | return rc; |
98 | } |
99 | EXPORT_SYMBOL_GPL(badrange_add); |
100 | |
101 | void badrange_forget(struct badrange *badrange, phys_addr_t start, |
102 | unsigned int len) |
103 | { |
104 | struct list_head *badrange_list = &badrange->list; |
105 | u64 clr_end = start + len - 1; |
106 | struct badrange_entry *bre, *next; |
107 | |
108 | spin_lock(lock: &badrange->lock); |
109 | |
110 | /* |
111 | * [start, clr_end] is the badrange interval being cleared. |
112 | * [bre->start, bre_end] is the badrange_list entry we're comparing |
113 | * the above interval against. The badrange list entry may need |
114 | * to be modified (update either start or length), deleted, or |
115 | * split into two based on the overlap characteristics |
116 | */ |
117 | |
118 | list_for_each_entry_safe(bre, next, badrange_list, list) { |
119 | u64 bre_end = bre->start + bre->length - 1; |
120 | |
121 | /* Skip intervals with no intersection */ |
122 | if (bre_end < start) |
123 | continue; |
124 | if (bre->start > clr_end) |
125 | continue; |
126 | /* Delete completely overlapped badrange entries */ |
127 | if ((bre->start >= start) && (bre_end <= clr_end)) { |
128 | list_del(entry: &bre->list); |
129 | kfree(objp: bre); |
130 | continue; |
131 | } |
132 | /* Adjust start point of partially cleared entries */ |
133 | if ((start <= bre->start) && (clr_end > bre->start)) { |
134 | bre->length -= clr_end - bre->start + 1; |
135 | bre->start = clr_end + 1; |
136 | continue; |
137 | } |
138 | /* Adjust bre->length for partial clearing at the tail end */ |
139 | if ((bre->start < start) && (bre_end <= clr_end)) { |
140 | /* bre->start remains the same */ |
141 | bre->length = start - bre->start; |
142 | continue; |
143 | } |
144 | /* |
145 | * If clearing in the middle of an entry, we split it into |
146 | * two by modifying the current entry to represent one half of |
147 | * the split, and adding a new entry for the second half. |
148 | */ |
149 | if ((bre->start < start) && (bre_end > clr_end)) { |
150 | u64 new_start = clr_end + 1; |
151 | u64 new_len = bre_end - new_start + 1; |
152 | |
153 | /* Add new entry covering the right half */ |
154 | alloc_and_append_badrange_entry(badrange, addr: new_start, |
155 | length: new_len, GFP_NOWAIT); |
156 | /* Adjust this entry to cover the left half */ |
157 | bre->length = start - bre->start; |
158 | continue; |
159 | } |
160 | } |
161 | spin_unlock(lock: &badrange->lock); |
162 | } |
163 | EXPORT_SYMBOL_GPL(badrange_forget); |
164 | |
165 | static void set_badblock(struct badblocks *bb, sector_t s, int num) |
166 | { |
167 | dev_dbg(bb->dev, "Found a bad range (0x%llx, 0x%llx)\n" , |
168 | (u64) s * 512, (u64) num * 512); |
169 | /* this isn't an error as the hardware will still throw an exception */ |
170 | if (badblocks_set(bb, s, sectors: num, acknowledged: 1)) |
171 | dev_info_once(bb->dev, "%s: failed for sector %llx\n" , |
172 | __func__, (u64) s); |
173 | } |
174 | |
175 | /** |
176 | * __add_badblock_range() - Convert a physical address range to bad sectors |
177 | * @bb: badblocks instance to populate |
178 | * @ns_offset: namespace offset where the error range begins (in bytes) |
179 | * @len: number of bytes of badrange to be added |
180 | * |
181 | * This assumes that the range provided with (ns_offset, len) is within |
182 | * the bounds of physical addresses for this namespace, i.e. lies in the |
183 | * interval [ns_start, ns_start + ns_size) |
184 | */ |
185 | static void __add_badblock_range(struct badblocks *bb, u64 ns_offset, u64 len) |
186 | { |
187 | const unsigned int sector_size = 512; |
188 | sector_t start_sector, end_sector; |
189 | u64 num_sectors; |
190 | u32 rem; |
191 | |
192 | start_sector = div_u64(dividend: ns_offset, divisor: sector_size); |
193 | end_sector = div_u64_rem(dividend: ns_offset + len, divisor: sector_size, remainder: &rem); |
194 | if (rem) |
195 | end_sector++; |
196 | num_sectors = end_sector - start_sector; |
197 | |
198 | if (unlikely(num_sectors > (u64)INT_MAX)) { |
199 | u64 remaining = num_sectors; |
200 | sector_t s = start_sector; |
201 | |
202 | while (remaining) { |
203 | int done = min_t(u64, remaining, INT_MAX); |
204 | |
205 | set_badblock(bb, s, num: done); |
206 | remaining -= done; |
207 | s += done; |
208 | } |
209 | } else |
210 | set_badblock(bb, s: start_sector, num: num_sectors); |
211 | } |
212 | |
213 | static void badblocks_populate(struct badrange *badrange, |
214 | struct badblocks *bb, const struct range *range) |
215 | { |
216 | struct badrange_entry *bre; |
217 | |
218 | if (list_empty(head: &badrange->list)) |
219 | return; |
220 | |
221 | list_for_each_entry(bre, &badrange->list, list) { |
222 | u64 bre_end = bre->start + bre->length - 1; |
223 | |
224 | /* Discard intervals with no intersection */ |
225 | if (bre_end < range->start) |
226 | continue; |
227 | if (bre->start > range->end) |
228 | continue; |
229 | /* Deal with any overlap after start of the namespace */ |
230 | if (bre->start >= range->start) { |
231 | u64 start = bre->start; |
232 | u64 len; |
233 | |
234 | if (bre_end <= range->end) |
235 | len = bre->length; |
236 | else |
237 | len = range->start + range_len(range) |
238 | - bre->start; |
239 | __add_badblock_range(bb, ns_offset: start - range->start, len); |
240 | continue; |
241 | } |
242 | /* |
243 | * Deal with overlap for badrange starting before |
244 | * the namespace. |
245 | */ |
246 | if (bre->start < range->start) { |
247 | u64 len; |
248 | |
249 | if (bre_end < range->end) |
250 | len = bre->start + bre->length - range->start; |
251 | else |
252 | len = range_len(range); |
253 | __add_badblock_range(bb, ns_offset: 0, len); |
254 | } |
255 | } |
256 | } |
257 | |
258 | /** |
259 | * nvdimm_badblocks_populate() - Convert a list of badranges to badblocks |
260 | * @nd_region: parent region of the range to interrogate |
261 | * @bb: badblocks instance to populate |
262 | * @range: resource range to consider |
263 | * |
264 | * The badrange list generated during bus initialization may contain |
265 | * multiple, possibly overlapping physical address ranges. Compare each |
266 | * of these ranges to the resource range currently being initialized, |
267 | * and add badblocks entries for all matching sub-ranges |
268 | */ |
269 | void nvdimm_badblocks_populate(struct nd_region *nd_region, |
270 | struct badblocks *bb, const struct range *range) |
271 | { |
272 | struct nvdimm_bus *nvdimm_bus; |
273 | |
274 | if (!is_memory(dev: &nd_region->dev)) { |
275 | dev_WARN_ONCE(&nd_region->dev, 1, |
276 | "%s only valid for pmem regions\n" , __func__); |
277 | return; |
278 | } |
279 | nvdimm_bus = walk_to_nvdimm_bus(nd_dev: &nd_region->dev); |
280 | |
281 | nvdimm_bus_lock(dev: &nvdimm_bus->dev); |
282 | badblocks_populate(badrange: &nvdimm_bus->badrange, bb, range); |
283 | nvdimm_bus_unlock(dev: &nvdimm_bus->dev); |
284 | } |
285 | EXPORT_SYMBOL_GPL(nvdimm_badblocks_populate); |
286 | |